Human mammary gland associated antigens. Lack of D-type retravirus-induced antigens.

Antisera against tumor-associated and organ-specific antigens of human mammary glands, as well as mammary carcinoma patient sera were used in cross-reactions with the test-system for a nucleoid antigen of Hep-2 retravirus. None of the antigens, revealed in mammary carcinomas and human milk seems to be either viral structural, or virus-induced cellular antigen. No cross-reactivity was revealed between preparations, containing A-type particles, isolated from Hep-2 cells and human milk and mammary carcinomas. Cell surface antigen, nonidentical to viral structural antigens, was detected in Hep-2 cells. It proved to be shared by E16b and some other stable cell lines, however it cannot be detected in mammary fibroadenomas, positive for the D-type nucleoid antigen, and in mammary carcinomas. Only gastric carcinoma homogenates exhibited reaction of identity with the cell surface antigen, shared by Hep-2 and E16b cells. It suggests that some common stem cells might be involved in its synthesis, rather than D-type retravirus genome. This question is worth a special investigation. The findings obtained show the genome of D-type retravirus is repressed in mammary carcinomas in contrast with fibroadenomas, when synthesis of nucleoid antigens was revealed by ILYIN [7].